1. Field of the Invention
The present invention relates to a fan, and in particular, relates to a centrifugal fan.
2. Description of the Related Art
Portable computers (for example, tablet computers or ultrabooks) are extremely thin, and the inner space therein is limited. The dimensions of the centrifugal fan disposed in the portable computer have decreased, and the space between the centrifugal fan and other elements inside of the portable computer has reduced. The heat dissipation effect of the centrifugal fan has therefore deteriorated. Particularly, with limited inner space, the output flow of the centrifugal fan is not uniformly output from the outlet, and the heat dissipation effect has worsened.
TW Patent No. I262991 discloses a centrifugal fan with radial auxiliary inlets formed on a side wall of a housing of the centrifugal fan. However, in TW Patent No. I262991, the radial auxiliary inlets face to an impeller of the centrifugal fan, and the radial auxiliary inlets are located in a low pressure area of the centrifugal fan. Therefore, in TW Patent No. I262991, there is eddy flow is undesirably higher, and the input flow rate is undesirably lower.